Instrument for determining the distinctness of image of a paint film

Abstract

A portable instrument quantitatively determining the distinctness of image of a sample paint film by providing comparison of the film with several standard films of known distinctness of image is provided. The instrument displays the sample and one of the standards within an enclosed casing while an image forming pattern is projected simultaneously on both by a light source within the instrument. By changing the standard which is displayed, an observer compares the distinctness of image of the sample with the known values of several standards until a match is found.

What is claimed is: 
     
       1. An instrument for determining the distinctness of image of a sample paint film by providing comparison with a plurality of standard paint films comprising: a base which is at least partially hollow having a first opening, for displaying the sample, which extends vertically through both the top and bottom surfaces of said base and having a second opening in the top surface, adjacent to the first opening;   a casing, having a viewing aperture therein, mounted on said base and covering at least the portion thereof containing the two openings, said aperture being positioned such that it affords a line of sight to said openings at an angle of 15-30 degrees with the normal to said base;   a light source fixed within said casing above the openings in said base;   display means movably mounted within the hollow portion of said base for displaying a plurality of standard paint films through the second opening of said base; and   image means, located within said casing between said light source and the openings in said base, for providing an image forming pattern capable of being projected by said light source onto the sample and standard through the openings in said base.   
     
     
       2. The instrument of claim 1 wherein said image means comprises: a diffuser plate, mounted parallel to said base;   a clear panel, under said diffuser plate and parallel thereto; and   a transparency carrying the image forming patterns sandwiched between said diffuser plate and said clear panel.   
     
     
       3. The instrument of claim 1 wherein said display means is a turntable rotatably mounted within the hollow portion of said base, said turntable having the standard paint films mounted thereon such that rotating said turntable allows each standard to be displayed through the second opening of said base without obstructing the first opening therein. 
     
     
       4. The instrument of claim 1 wherein said display means is a slip-panel slidably mounted within the hollow portion of said base, said slip-panel having the standard paint films mounted thereon so that sliding said slip-panel allows each standard to be displayed through the second opening of said base. 
     
     
       5. An instrument for determining the distinctness of image of a sample paint film by providing comparison with a plurality of standards comprising: a base which is at least partially hollow having a first opening, for displaying the sample, which extends vertically through both the top and bottom surfaces of said base and having a second opening in the top surface, adjacent to the first opening;   a casing having a viewing aperture therein mounted on said base and covering at least the portion thereof containing the two openings, said aperture being positioned such that it affords a line of sight to said openings at an angle of 15-30 degrees with the normal to said base;   a light source fixed within said casing above the openings in said base;   a turntable rotatably mounted within the hollow portion of said base, said turntable having standard paint films mounted thereon such that rotating said turntable allows each standard to be displayed through the second opening of said base without obstructing the first opening therein;   a diffuser plate mounted in said casing below said light source and parallel to said base;   a clear panel under said diffuser plate and parallel thereto; and   a transparency carrying an image forming pattern sandwiched between said diffuser plate and said clear panel, said transparency said diffuser plate and said clear panel being positioned such that the image forming pattern is capable of being projected by said light source onto the sample and standard through the openings in said base.